Just a quick note to anyone planning on going to bulgaria ... DO NOT buy a
vivatel sim card... the reason being is that the operator installed their network cells throught the conutry, on grounds of an old AMTS licence, and now they have been forced to relocate most of their network equipment...

Therefore there is constant signal loss in sofia, and in most of the outer parts of the city you will not be able to make or receive calls as the cells are in diagnostic mode